


Amaterasu's Heart Fire

by Kalira



Category: Naruto
Genre: (Kishi did it first though), (non-detailed), (was mean), A little, Angst, Canonical Eye Trauma, Community: trope_bingo, Happy Ending, I messed with the timeline, KakaObi Week 2020, Kannabi Bridge Mission, Kid Hatake Kakashi, Kid Uchiha Obito, M/M, Panic Attacks, Rejection, Trope Bingo Round 14, Uchiha Legends, entirely made up in-universe mythology
Language: English
Status: Completed
Published: 2020-02-14
Updated: 2020-02-14
Packaged: 2021-02-27 19:48:28
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,658
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22721230
Author URL: https://archiveofourown.org/users/Kalira/pseuds/Kalira
Summary: Every Uchiha knows that one day they may be lucky enough to lay eyes on the one person who sparks Amaterasu's fire in their heart. Few are so lucky to find them so young as Obito . . . though few would envy him that, and the trials it brings him over the years.
Relationships: Hatake Kakashi & Uchiha Shisui, Hatake Kakashi/Uchiha Obito
Comments: 8
Kudos: 270
Collections: KakaObi Week 2020, Kalira's KakaObi Week Stories (2020), Trope Bingo Round 14, Trope Bingo: Round Fourteen





	Amaterasu's Heart Fire

**Author's Note:**

> Written for [KakaObi Week 2020](https://kakaobiweek.tumblr.com/post/188302902444/kakaobi-week-2020), Day 5: Fate
> 
> I am also using it to mark off the space 'AU: Fairytale/Myth' on my Trope Bingo [board](https://kalira.dreamwidth.org/24550.html).
> 
>  **Warning:** While not terribly detailed, Kakashi suffers a panic attack in the third scene; a friend helps him process it and it fades.

Kakashi grit his teeth and whirled on his irritating, clumsy, _not at all stealthy_ shadow - at least Gai was _good_ at this - with a snarl. “Why?” he demanded. “Why won’t you just _leave me alone_ , I know you’ve always been _dead last_ but aren’t you smart enough even to take a hint?”

Obito rocked back on his heels, breath catching and dark eyes wide. “I. . .”

“I don’t _want you around me_ , you idiot.” Kakashi snapped, lifting his jaw. “That _has_ to be obvious.”

“It. . . It is.” Obito said softly. “More than.”

Kakashi wasn’t quite sure if he really said _I’m sorry_ in that barely-there, huffed breath or not. “Then why?” Kakashi asked impatiently.

“Because. . . Because one of my ancestors made a deal.” Obito said, and Kakashi frowned.

“What? What has that got to do with-”

“A deal so that. . . So that every Uchiha would know,” Obito said, his voice falling into an almost singsong pattern and his expression steadying a little, “because every Uchiha’s heart holds Amaterasu’s fire, and every Uchiha’s eyes search for the one who sparks it, our ancestor made a deal so that every Uchiha would know. . .”

Kakashi’s stomach knotted, his own heart feeling like it was lodged in his throat, thumping uncomfortably.

“Who we’re to belong with.” Obito said quietly. “Who the kami laid out to be our match, to spark that heart’s fire but also to keep it from flaring and killing us.”

He raised his gaze to meet Kakashi’s own again, and Kakashi’s heart thumped harder as he felt a surge of nausea. “ _No._ ” Kakashi said hard and fast. “That’s- How could you even think I would ever be that? That I would ever _want_ that?”

“Kakashi- That’s not- I just. . .” Obito looked crestfallen and a little pasty. “You’re the one. I’m not asking- Please, it’s my-”

Kakashi didn’t wait, bolting away from Obito, knowing there was not the smallest chance Obito would be able to keep up, or _catch_ up to him.

* * *

It wasn’t as though Kakashi could exactly stay _away_ from Obito - not when they were in classes together, and then on a _team_ together; Obito was a regrettable constant in Kakashi’s life and had been for some time - but he put even more effort into minimising the time Obito could possibly be around him than before.

Obito, he realised with some surprise, never seemed to try to work around it, or get too close to him. It seemed, at the same time he had given up that last revelation Kakashi had never wanted to know, Obito had finally taken the hint . . . but he still _watched_ Kakashi, trailed after him at times, even if Obito never again approached Kakashi the way he had used to.

Kakashi tried to put it out of his mind, to refuse even that _memory_ , but even as years passed - and Obito remained the frustrating, flaily, dead last irritant he had always been - Kakashi could never quite forget Obito’s muddled, not quite sensible words, his claim of what Kakashi was to him.

* * *

“Ne . . . Shi-kun?”

Shisui looked up with a smile. “Yes, senpai?”

His open expression and cheerful tone made it both easier and harder to ask. Kakashi strangled down a nauseating twist in his middle and nodded once, forcing his heartrate to calm as he took several deep, focused breaths. “. . .what is Amaterasu’s heart fire?” he asked, studiously careless, inspecting the edge of a kunai.

Shisui startled. “Kakashi- It- Where did you. . .” he trailed off with a sigh that faded into a dreamy noise, leaning against the tree trunk behind him. “It’s . . . the spirit of every Uchiha, the gift of the kami . . . and our death if we’re foolish; it’s what makes us strong but also what _breaks_ us. . .”

Kakashi resisted the urge to squirm anxiously. “And. . . The one who sparks it?”

“To be the one who sparks Amaterasu’s fire in someone’s heart. . .” Shisui smiled a little more, glancing up through his lashes and then closing his eyes. “It’s a special thing, the perfect match the kami made, a gift one cannot turn down, to be that spark for another. It would be unthi- Kakashi-senpai? _Kakashi_ , fuck, are you-”

Kakashi couldn’t hear Shisui properly any more, his pulse roaring in his ears as he tried to stop retching, remembering Obito’s _stricken_ face as he ran that day. He bent forwards over his knees, fingers curling into the grass, struggling to breathe.

“Kakashi! Fuck, fuck, I didn’t- I’m sorry!” Shisui’s hands were warm and solid as he grabbed at Kakashi’s shoulders. “Breathe! I didn’t realise you. . .” He cupped Kakashi’s face, catching his gaze. “Look at me.”

“Don’t genjutsu me.” Kakashi wheezed, and Shisui shook his head.

“No, no, of course I won’t.” Shisui rested their brows together. “Just breathe with me, okay?” he asked softly, clasping Kakashi’s shoulders. He breathed in time with Shisui, their breath mingling, and it calmed him slowly. “I’m sorry. I didn’t realise. . . Someone’s told you that _you’re_ their heart’s spark, haven’t they?”

Kakashi swallowed against a fresh wave of nausea. “I- I rejected- How could I- You just said, too, that it’s unthinkable, what did I _do_ to him, Shisui?” he asked, chest aching.

“Oh kami, Kakashi, you can turn him down. It’s not something you _have_ to reciprocate or are forbidden to- That would be fucked up.” Shisui said, clasping his arm.

“You just said-”

“It’s a romantic notion, but it’s _not_ a duty, fuck.” Shisui squeezed harder. “I wouldn’t have put it like that if I’d realised someone had-” He paused. “. . .Obito-kun.”

Kakashi cringed.

“Of course. No wonder he follows you so hard. . .” Shisui shook his head. “Look, Kakashi, it’s _not_ a requirement - if you don’t have feelings for him, if you don’t . . . love him, then it means nothing from your side. And it’s _not your fault_ if you don’t feel anything for him.”

Kakashi shook his head a little, and Shisui shook him firmly. “Look at me. It’s _not_. It _sucks_ , but it’s the way we’re built, and sometimes we love people who don’t _want_ to house the spark, and it’s _not_ something you can just. . . You have to want it, Kakashi. Or it means nothing.”

“I was cruel to him.” Kakashi said thinly.

“Then that was a dick move,” Shisui said, and Kakashi was startled into a laugh, “but it’s understandable. You didn’t have a clue what he asked you, did you? Besides,” he added before Kakashi could do more than shake his head, let alone say that Obito hadn’t exactly _asked_ anything, “you’re kind of a dick, Kakashi.”

“Fuck you.” Kakashi laughed weakly.

“No. Besides,” Shisui smiled crookedly, “you’re not _my_ spark for Amaterasu’s fire.”

Kakashi laughed again, and if it was maybe a little unbalanced, Shisui said nothing, wrapping an arm around him and rubbing his back, giving him something to focus on.

* * *

Even after that, with Kakashi unwilling - _unable_ \- to offer anything more than his silence, and Obito unable to stop following him but equally unable to ask - or perhaps to hope - for anything more than Kakashi’s tolerance. . .

Nothing changed, and perhaps nothing _would_ have changed, if it hadn’t been for a disaster that could have been the breaking of them in so many more ways.

* * *

“So much for the Uchiha’s greatest strength.” Kakashi said, ignoring Rin’s shocked gasp and then her sharp scolding equally well. Kakashi clasped Obito’s shoulder, one of the only bits of him that was reachable with the rockslide trapping him. “Are you just going to let yourself- be taken away?” he finished with a faltering hitch.

“It’s- _Kakashi._ ” Obito gave a weak huff that could have been a laugh or a sob. “It’s not a magic trick. I can’t. . . I only wish that. . .” he trailed off, his eye slowly closing.

“Some greatest strength.” Kakashi sneered, then caught his breath and, ignoring Rin with some difficulty, tugged down his mask. Obito startled, and Kakashi bent, kissing his cheek. “You’re going to let yourself be taken away from me? So easily?” he asked softly, lips brushing Obito’s dirty, bloodied cheek.

Obito’s breath caught. “Ka- _Kakashi._ ”

“If I’m the spark for Amaterasu’s heart fire for you,” Kakashi said, voice shaking a little, clasping Obito’s hand, “then _let it fucking spark_ , Obito; _get yourself out of there_.”

Kakashi was too weak from the running battles, Rin too weak already, and Obito too badly trapped to risk unearthing him more piecemeal; they could have instead triggered a further slide that would crush him completely.

Heat sparked between Kakashi’s gloved palm and Obito’s, a fierce burning that was somehow just shy of pain. His eye widened as he sat straight, but he didn’t try to turn Obito’s hand loose as Obito gasped, Sharingan eye wide and spinning in a pinwheel-blur, his chakra swelling so thick it was momentarily hard to _breathe_ from the weight of it. Stronger than Kakashi had ever felt from Obito.

Kakashi flinched back, closing his eye against the sudden blinding brightness as rock groaned and grated. He clung to Obito’s hand, panic sparking, but Obito clung back just as fiercely, and Kakashi took reassurance from that, even as he tried to call out and found his breath stolen before he could voice so much as Obito’s name.

When the brilliance faded enough it no longer hurt even through his closed eyelid, Kakashi opened his eye to find Obito struggling upwards, free of the rockslide that was now a heap of far more crumbled rock and dirt, gasping, his right arm limp at his other side, which he was favouring carefully, but didn’t look so . . . broken as Kakashi would have feared if he’d thought Obito could even get free of the rocks.

“Oh _kami_ , Obito-kun!” Rin cried, reaching for him shakily, her fingers glowing green.

“ _Now_ you want me?” Obito wheezed as he slouched closer to Kakashi, sniffling. “ _Kami_ , Kakashi, I- I cost you an _eye_ , I have to be the worst Uchiha _ever_ , do you understand what that- that even _means_ -”

“Then I guess it’s a good thing I’m not an Uchiha.” Kakashi said, twining both his hands around Obito’s. He fell silent, eyes wide - or at least, his eye was wide on his uninjured side, and the other eyelid twitched and tried to rise as well. “Besides,” he squeezed Obito’s hand tighter, “I took the wound to save you. I’d do it again,” he said, and Obito shuddered once, then froze, “so what does _that_ mean, to an Uchiha?” He lifted his jaw a little, his remaining eye narrowing.

The other ached horribly beneath the bandages, but Kakashi had been ignoring that for some time, he could continue to do so.

“ _Kakashi._ ” Obito all but whimpered, and Kakashi leaned their heads together gently. His own was throbbing, from the injury - his slashed, empty eye - and exertion - he was low on chakra and exhausted from fighting and running - and the brightness of the flame - Amaterasu’s fire? - Obito had called, and. . .

“You- You’re all right.” Rin said, and Kakashi’s heart leapt. “ _How_ are you- I was afraid-” Her breath caught and she nearly pulled Obito away from Kakashi as she flung her arms around him in an embrace.

Obito hissed, wincing, but returned her hug. Only with his battered right arm, which he winced further at moving, not pulling his left hand from Kakashi’s clasp. “I. . . My heart was sparked with Amaterasu’s fire.” he said, a little muddled, and looked to Kakashi. He ducked his head, swallowing a whine. “It was . . . the first time. First is strongest. Except. . .” He shook his head.

“I’m glad you’re all right.” Kakashi said quietly even as Rin drew back, leaning in again.

Obito tentatively sank sideways to rest against him, their heads together again.

“Well. He’s not broken,” Rin said, gathering herself visibly, “he _definitely_ needs to get to the hospital, regardless. You were trapped in a _rockslide_ , one _designed_ to crush whoever it caught, whatever you managed and I’m so glad you’re alive,” she paused and hugged him again, “you aren’t exactly fine.”

“Better than fine.” Obito murmured, dark eyes meeting Kakashi’s, but he didn’t really argue, either.

* * *

Kakashi brushed a hand just shy of Obito’s shoulder again, able to feel his chakra humming though not his pulse - not without touching him - then drew away. He looked outside, then drew the curtains against the sun again - Obito was resting, probably trying to sleep.

He returned to the bed and tucked another blanket up over Obito, because the hospital carried a chill - he shivered - then turned around and went to neaten the little gifts and cards Obito had collected since they’d returned from their mission. Shisui had brought both of them fruit, and a new book; Rin had brought flowers; Minato-sensei was here every day, every moment he could spare, Kakashi thought, and he was responsible for both the plush cat Obito refused to admit he liked but kept mysteriously ending up in his bed, and the plush dog with a rakish eyepatch which Kakashi had put on a shelf nearby, watching the room with its remaining bright eye.

There were more presents from people Kakashi didn’t know, probably the ones Obito was forever helping. Kakashi had cards or trinkets from a few people he’d run missions with when away from his team; like Shisui.

“Kakashi.” Obito said, and Kakashi jumped, turning towards the bed. “You’re. . .” He smiled faintly. He’d been doing that; the half-formed sentences and happy, shocked expressions, since he woke up here the first day after they got back.

The second night in the hospital Kakashi had heard him whimpering in the dark, and when he’d clasped Obito’s hand, heard him whisper heartachingly desperate thanks that Kakashi was _here_ with him. He tried not to think about it.

Kakashi huffed softly and moved to pour a fresh glass of water for Obito.

“Kakashi,” Obito called, and he looked over, “kami, Kakashi, sit _down_ , you’re- You lost an _eye_ less than a week ago and you took on more than half that mission yourself.”

“I’m fi-”

“Please?” Obito wheedled, looking hopeful and a little pathetic. He held out his right hand - they’d taken the bandages off this morning, and the skin was raw and pink and covered with lines that would probably scar; it was the same all up his right side to his face. He glanced at his hand, flexing his fingers, then dropped it, looking away. “I worry about you too. And you’re- Please come. . .”

Kakashi shifted awkwardly, then moved across to Obito’s bed. “Well. If you want me to- _Move._ ” He huffed, ducking his chin.

Obito looked up at him, wide-eyed, then grinned, bright and open. He slid over slowly - the plush cat slid down past his shoulder and he pinked - and Kakashi climbed up beside him, wincing. He moved the plush cat to sit on Obito’s stomach and lay down beside him, turned on his side facing Obito.

“What do you want?” Kakashi asked quietly, and Obito shifted a little as though _he_ would turn as well. Kakashi put out a hand to stop him; he was on Obito’s right side, and he might be healing well but he shouldn’t strain himself that much yet.

Obito clasped Kakashi’s hand, tugging it up over his chest, and shook his head. “I don’t want. . . I just. . .” He swallowed. He shook his head, not speaking any more, and Kakashi sighed softly.

“Rest. Idiot.” Kakashi said, shifting a little closer and nuzzling Obito’s shoulder gently.

“You too, Bakashi.” Obito huffed, and squeezed his hand. “All I want,” he added more softly, “is my spark, to have Amaterasu’s heart fire, to have from the one who sparks it in me the same. . . I found you so young, you know, most people. . . Even if they _do_ find. . . But then-” he faltered.

“I’m. . .” Kakashi bit the inside of his cheek. “I’m here.”

“That’s all I want. Thank you.” Obito said, squeezing his hand. Kakashi returned the clasp gently and Obito shifted until their heads rested together on the pillow.

**Author's Note:**

> So I had this prompt tagged as one I wanted to write for, but have had no ideas - until yesterday at just after 4pm when the first scene in this sprang fully-formed to mind, demanding to be written. It's now 1:30pm and I'm posting this after spending much of yesterday evening and this morning hammering out story.


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